Dennis quit with about 80km left before the two big climbs in Stage 12,prompting Bahrain-Merida to open an investigation.

According to the French TV station broadcasting the race,Dennis had an argument with officials in the team car.

Stangelj said Dennis'condition was good enough to perform,adding he was not aware of any kind of argument that could have triggered the rider's decision.

Dennis's withdrawal was even more surprising as it came a day before Friday's short time trial in Pau where,given his time trial pedigree,he would have been an obvious favourite alongside defending Tour champion Geraint Thomas.

Stangelj was not aware of any complaint from Denis in regards to his time trial equipment and also dismissed suppositions that Dennis could have been frustrated with his role in the team.

Bahrain-Merida's main goal at the Tour this year was to fulfil former Tour champion Vincenzo Nibali's ambition to fight for a podium finish.

"I never asked him to bring the water bottles in the race,"Stangelj said. "Actually,I even told him yesterday and today that he should save energy for the time trial."

When asked if Dennis had been difficult to work with before,Stangelj said:"it's difficult to answer this question.

"But I never have hard discussions with him,"he insisted. "We always found a solution when it was needed."

Stangelj explained that after Dennis stopped at the feed zone,he was not immediately able to reach out to him because he had already passed that point on the route and could not turn back with his car.

He finally managed to get his rider on the phone after another car from the team arrived next to him.

AP